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(11) | EP 1 189 344 A3 |
(12) | EUROPEAN PATENT APPLICATION |
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(54) | Lumped element filters |
(57) Thin film epitaxial high temperature superconductors are patterned to form lumped
capacitors and inductors on low loss substrates. A ground plane (20), preferably of
high temperature superconductive materials or high conductivity materials, such as
gold or copper is placed on the substrate opposite to the patterned elements. Various
structures such as a planar spiral conductor (24), or a zig-zag or serpentine conductor
(42) can be formed. Additional structures such as narrow band reject filters (52)
and bandpass filters can be formed. Chebyshev, elliptic and quasi-elliptic filters
can be formed from a plurality of band-reject structures (116). Similarly, quasi-elliptical
bandpass filters using a plurality of series connected bandpass structures with planar
cross-couplings (134, 136, 138) can be formed. |